THE ROLE OF POWER CONTROL IN CDMA IN LOW EARTH ORBIT SATELLITES

摘要

In recent years the use of small multi-mission satellites(SMMS) in Low Earth Orbit(LEO) for making voice,data and E-mail communications has been grown extensively. Low production cost, Low cost of lunching and low transmission power due to it's low orbit of these satellites are some reasons for their vast usage. How over because of their low orbit they need to turn several times around the earth every day and so are only visible in each area for short period of time. Therefore,the aim on these satellites is to increase the numbers of user during visibility period. In this paper we have shown that under specific conditions(such as power control) CDMA have higher capacity compare to FDMA and TDMA. In addition they have other advantage like anti-jam, anti-multi path, soft capacity and etc which will be addressed in this paper.